“Restrepo,” a documentary that sticks close to a company of American soldiers during a grueling 14-month tour of duty in an especially dangerous part of Afghanistan, is an impressive, even heroic feat of journalism. Not that the filmmakers — Sebastian Junger, an adventurous reporter perhaps best known as the author of “The Perfect Storm,” and Tim Hetherington, a photographer with extensive experience in war zones — call attention to their own bravery. They stay behind the portable high- and standard-definition video cameras, nimble flies on a wall that is exposed to a steady barrage of bullets.

Hanging out with the members of Battle Company in their hilltop outposts in the Korangal Valley between May 2007 and July 2008, Mr. Junger and Mr. Hetherington recorded firefights, reconnaissance missions, sessions of rowdy horseplay and hours of grinding boredom. Afterward, when the tour was done, the filmmakers conducted interviews in which the soldiers tried to make sense of what they had done and seen. There is nothing especially fancy or innovative here, just a blunt, sympathetic, thorough accounting of the daily struggle to stay alive and accomplish something constructive.

Any viewer superficially acquainted with the literature and cinema of modern war will have a sense of the peril and tedium that define a soldier’s daily experience, and the wars in Afghanistan and Iraq have spawned a number of serious and well-made films, both fictional and not. What distinguishes “Restrepo” — which belongs with “The Hurt Locker” and “Gunner Palace” on the short shelf of essential 21st-century combat movies — is not only its uniquely intensive focus on a small group of men in a particular time and place, but also its relentless attention to the lethal difficulty of their work.

The setting is the Korangal Valley, a mountainous, sparsely populated area in Eastern Afghanistan that, at least at the time, was seen as a region of prime strategic importance. (American forces withdrew from the valley this April.) It was also an exceedingly hazardous place for American soldiers, with almost every day bringing a fresh engagement, to use the military term of art that basically means being shot at by the enemy and shooting back.

In addition to defending their encampments, the company’s men built a new outpost, and in the midst of regular skirmishes with the Taliban and other insurgents they went about the sometimes confusing business of trying to win hearts and minds. At weekly meetings with local elders and in more informal encounters, the soldiers, led by Capt. Dan Kearney, tried to overcome suspicion and resentment, and to persuade Korangal citizens that the American presence would bring jobs, improved infrastructure and other good things.

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Capt. Dan Kearney of Battle Company meeting with Afghan elders from the Korangal Valley in the documentary “Restrepo.”Credit
Outpost Films/National Geographic Entertainment

Like most movies of its kind, “Restrepo” avoids any explicit political discussion. The soldiers can’t wait to leave Korangal but are also determined to carry out their duties, and they don’t have the time or inclination to reflect on larger causes and contexts. But in their close observation of just how the war is being conducted, Mr. Junger and Mr. Hetherington provide plenty of grist for political argument. They also reveal one of the irreducible, grim absurdities of this war, which is the disjunction between its lofty strategic and ideological imperatives and the dusty, frustrating reality on the ground.

What are these guys doing there? It’s hard to watch this movie without asking that basic, hard question. Captain Kearney and his men address it in practical terms. Convinced that his predecessor badly mishandled the assignment, the captain sets out to expand the American footprint and improve relations with the local residents. The showpiece of his efforts is the outpost that gives the movie its name, which in turn takes its name from Pfc. Juan S. Restrepo, a medic who was killed early in the deployment.

Private Restrepo is seen in shaky video taken before his tour began — a playful, charismatic young man (only 20 at the time of his death) who describes himself as “loving life and getting ready to go to war.” As the movie goes on, the heartbreak latent in this simple declaration becomes more acute, as the soldiers deal with their fears and then, during a field assignment called Operation Rock Avalanche, the brutal realization of those fears. The filmmakers are circumspect in what they show, taking care to avoid focusing on the wounded and the dead, but the impact of battlefield death and injury has rarely been captured so unsparingly. And though it is composed in the prose of hand-held video, “Restrepo” has the spare, lyrical force of an elegy, inscribing a place for its characters in a tradition of war poetry stretching back to the epics of the ancient world.

What you come away with, above all, is a sense of the fragile, indelible individuality of the soldiers, whose names, faces and ways of talking are likely to stick in your mind for a long time. Some share their backgrounds — Specialist Misha Pemble-Belkin, for instance, reflects on the contrast between his pacifist, “hippie” upbringing and his violent profession — but others just speak matter-of-factly about stuff that happened in Korangal.

I don’t want to lecture, but as the war in Afghanistan returns to the front pages and the national debate, we owe the men in “Restrepo,” at the very least, 90 minutes or so of our attention. If nothing else, this film, in showing how much they care about one another, demands the same of us.

Produced and directed by Tim Hetherington and Sebastian Junger; directors of photography, Mr. Hetherington and Mr. Junger; edited by Michael Levine; released by National Geographic Entertainment. In Manhattan at the Angelika Film Center, Mercer and Houston Streets, Greenwich Village. Running time: 1 hour 34 minutes.